Parrothead & Disney Fanatic.
Spoke to reservations yesterday about possible upcoming trip and they told me for an August vacation park hops would require reservations as well as the initial park. After 2 pm he said you can hop to another park that has available reservations, he said people who stay onsite would have priority and would be most likely to be able to visit other parks except on very busy days. He said refunds would not be given to people who purchased hoppers and couldn't use them when i asked. The WDW webpage has not updated this yet.